Field of the Invention
The present invention relates to a color conversion data generation device, a color conversion data generation method, and a display device.
Description of Related Art
Various displays are used in professional work flows of video production and DTP (desktop publishing), and the same color reproduction is required between those different display products. In order to realize in a simplified manner, color management for performing the same color reproduction, there is a demand for realization of the same color reproduction by defining desired color reproduction as image quality parameters and batch-setting them on each display (performing LUT (look up table) import).
In relation to realization of this type of color reproduction, there has been disclosed a technique for performing 6-axis adjustment with use of LUT (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2013-232746).
However, as regards hue, value, and saturation among the parameters that are adjusted by means of 6-axis adjustment, there is a problem in that no common correction characteristic has been established between display products, and as a result, the same color reproduction cannot be obtained even if the same parameters are set on products of different manufactures.
On the other hand, the same color reproduction can be obtained between a number of display products if 6-axis adjustment is performed by means of a generic 3D LUT (three-dimensional lookup table) circuit. However, there is a problem in that image quality is more likely to deteriorate. The cause of image deterioration is inconsistency between the tone characteristic required in a general 6-axis correction algorithm, and the tone characteristic in a 3D LUT circuit. Specifically, a general 6-axis correction algorithm requests a 3D LUT circuit for analog continuous tone characteristic. However, since the tone characteristic in the 3D LUT circuit is a linear tone characteristic that connects only a few LUT correction points, it does not match with the requested characteristic.
As a result, in a case where the conventional 6-axis color correction algorithm is set on the 3D LUT circuit, image quality deterioration such as unnatural hue shift, tone jump, and color rolling occurs in gradations of intermediate colors. Since this type of image quality deterioration occurs only when the 6-axis correction algorithm uses the 3D LUT circuit, it cannot be verified with the 6-axis correction algorithm alone. Therefore, conventionally it has been difficult to avoid it.